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CLI (olc)

The olc command is the standalone, dependency-free way to work with Open Lakehouse Contracts. It validates any *.olc.yaml against the public JSON Schema and installs agent integrations — no runtime, no cloud, no framework required.

pip install open-lakehouse-contract
olc --version

Why it matters

  • A gate you can trust in CI. olc validate fails on the things that silently rot a contract estate — schema violations, and a discovery run that finds zero contracts (a misconfigured path that would otherwise pass green).
  • Portable by construction. It checks against the JSON Schema, so the same guarantee holds in any language or pipeline — the contract is the standard, not the tool.
  • Agent-ready in one step. olc init drops in assistant integrations safely, never overwriting divergent files without your say-so.

olc validate

Validate explicit files, or recursively discover every contract under a directory.

olc validate contracts/orders.olc.yaml        # one or more files
olc validate --root contracts                 # discover recursively
olc validate --root contracts --output json   # machine-readable for CI

Discovery fails when no contracts are found, so a mistyped path can't let a CI job pass silently — use --allow-empty only when an empty directory is genuinely expected. The YAML loader also rejects duplicate keys rather than silently keeping the last one.

Point at a specific schema (a pinned version, or a URL) with --schema:

olc validate contracts/orders.olc.yaml --schema schema/open-lakehouse-contract.schema.json

Exit code 0 = every contract valid; non-zero = at least one failure. That's the whole contract with CI.

olc init

Install assistant integrations (e.g. Claude, Codex) into a project, safely.

olc init --list                       # show what can be installed
olc init --tools claude,codex --dry-run
olc init --tools claude,codex

Existing identical files are left untouched. If a destination file differs, the whole install stops before writing anything — review and merge it yourself, or pass --force when replacement is intentional. No surprise overwrites.

Where olc ends and LakeLogic begins

olc validates and scaffolds a single portable contract. To run contracts (validate + quarantine + materialize across engines), or to validate the mesh registry that supplies contracts their shared defaults, use the LakeLogic reference framework and its lakelogic CLI — see LakeLogic CLI. The boundary is deliberate: the standard stays small and portable; the framework does the heavy lifting.